Carburetor froth-control device



Jan. 19, 1960 J. T. w. MOSELEY' CARBURETOR FROTHCONTROL DEVICE Filed Feb. 3, 1958 INVENTOR.

S T. W. MQSELEY 01,

AT ORNEYS United States Patent 2,921,175 CARBURETOR FROTH-CONTRQL DEVICE James T. W. Moseley, Grosse Micln, assignor to Holley Carburetor Company, Van Dyke, Mich, a corporation of Michigan Application February 3, 1958, Serial No. 712,825 Claims. (Cl. 261-72) The present invention relates to improved automotive carburetor structure making possible the better restarting of an engine following operation at elevated temperature. It does this by eliminating the effect of frothing or percolative foaming under the described condition, such as is likely to cause flooding or otherwise upset a proper fuel metering action.

Present day engine carburetors characterized by a liquid fuel or float bowl in heat transfer relation thereto, are subject to boiling and percolating, with resultant difliculty in restarting after high temperature operation, due to the tendency of fuel inthe condition of a relatively heavy froth or foam to issue upwardly from the fuel float bowl and through the balance tube or internal vent of the carburetor. This foam may pass directly to the primary intake passages of the carburetor metering line to cause flooding. 7

It is therefore an object of the invention toprovide a simple and inexpensive carburetor improvement by which the objectionable condition is avoided.

Another object of the invention is to provide a frothcontrolled carburetor construction, in which fuel foam issuing up the internal vent tube is confined, caused to revert to liquid form and returned directly to the float bowl, without possibility of escape to cause flooding.

More specifically, it is an object of the invention to provide a carburetor having an upright wall defining a reservoir wall surrounding the internal vent tube within the usual air cleaner, through which tube atmospheric pressure, as depressed by the flow-restrictive efiect of the air cleaner, is maintained in the float bowl. A lateral slotted passage of substantial size adjacent the base of said vent tube opens from its bore to the reservoir, through which passage frothed fuel as collected in the bore returns direct to the float bowl in liquid form.

The foregoing as well as other objects will become more apparent as this description proceeds, especially when considered in connection with the accompanying drawings illustrating a preferred embodiment of the invention, wherein:

Fig. 1 is a fragmentary view in side elevation, partially broken away and in vertical section along the line 11 of Fig. 2, showing the improvement of the invention as embodied in a conventional type of carburetor;

Fig. 2 is a fragmentary top plan view of the carburetor, being partially broken away and in horizontal section along the line 2-2 of Fig. 1; and

Fig. 3 is a fragmentary perspective view, also partially broken away, of the improvement.

The reference numeral generally designates a conventional type automotive carburetor to which the antifrothing provisions of the invention are applied. Typical standard components of such a carburetor include a lateral float bowl 11 in physical heat transfer relation to the carburetor proper, with a conventional spring-stabilized float 12 in bowl 11, there being an external automatic vent 13 in the top wall of the bowl 11; a choke housing 14 having an operating rod or link 15 connected to an operating arm on the shaft 17 of the choke valve 18; etc.

passage 22 formed in the carburetor body 23 and the passage 22 communicates laterally, through a horizontal:

connecting passage 24 in the body, with the top of the float chamber within bowl 11.

In accordance with the invention, the portion of the float body 23 on which the vent passage 22 is integrally formed is provided with a further integral, upstanding arcuate wall 26 surrounding the passage portion, as clearly indicated in Fig. 3, thus providing a reservoir 27 of substantial height and volumetric capacity in which the foam may be collected, breaking down to residual liquid form as it does. The passage portion 22 is provided with a vertically elongated slot 28 of substantial size adjacent the bottom of the reservoir, communicating the latter with the interior of the vent passage, as depicted in Fig. 1. I

Accordingly, upon restarting at an elevated temperature, the attendant percolation and resultant generation of froth or foam causes issuance of this foam upwardly into the vent passage and toward vent tube 20. The rising foam either passes laterally outwardly in its entirety through the slot 28 or, if it reaches the top of the tube 20, overflows into the reservoir 27. The relatively heavy foamed fuel thus collected breaks down in the reservoir to a residual liquid form, and in this form returns freely downwardly through the slotted passage 28 and lateral passage 24 to the interior of the float chamber 24. Thus, the desired depressed atmospheric pressure on the fuel bowl is maintained, without possibility of a disturbance of flooding or proper metering action as the result of the frothed fuel passing directly to the primary intake passages.

The drawing and the foregoing specification constitute a description of the improved carburetor de-frothing device in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. The improvement in a carburetor having an upwardly extending internal vent member communicating its float chamber with an upper space for the voiding of air and vapor to such space, in accordance with which improvement said carburetor has means receiving fuel rising in and emitted from said internal vent member, and means for the direct return of said emitted fuel to said float chamber.

2. The improvement in a carburetor having an upwardly extending internal vent member communicating its float chamber with an upper space for the voiding of air and vapor to such space, in accordance with which improvement said carburetor has a reservoir space receiving fuel rising in and emitted from said internal vent member, and means for the direct return of said emitted fuel to said float chamber.

3. The improvement in a carburetor having an upwardly extending internal vent member communicating its float chamber with an upper space for the voiding of air and vapor to such space, in accordance with which improvement said carburetor has a reservoir space surrounding said vent member and receiving and laterally confining frothed fuel rising in and emitted from said internal vent member, and means for the direct return of said emitted fuel to said float chamber.

4. The improvement in a carburetor having an upwardly extending internal vent member communicating Patented 'Jan. 19, 1960 3 its-float chamber witli-an' upperspace for'the voiding'of air and vapor to such. space, intaccordance with which improvement said carbureton has a reservoir space re ceiving fuel rising in and emitted from said internal vent member; and-said vent member has -a lateral froth return passage: opening: to said reservoir for' the direct. return of said emitted ifuel tossaidvfloat' chamber;-

5. The' improvement in 'a carburetor'having'an upwardl'yvextending internal vent member communicating its float chamber with'an upper space for the voiding,

of-air and vapor to such space, in accordance With which improvement. said: carburetor has azreservoir space surrounding said vent member and' receiving and laterally confiningirothed'fuel rising, in and emitted from said internal vent member, and said vent member has a lateral froth return passage openingkto said reservoir for the direct return of said emitted fuel to said float chamber.

References Cited t he file of this patent UNITED STATES PATENTS 2,444,454 Leaf July 6 1948 2,454,974 Mennesson Nov; 30, 1948 2,508,528- McPherson-mu", May. 23,1950 

